Abstract: This paper presents a numerical investigation on the variably accelerated motion behaviors and nonlinear aerodynamic characteristics of snow particles in air. Particle models with different sizes and densities are established by dynamic mesh technique. Based on the kinematic differential equation, free settlement and forced motion processes of idealized snow granules in stationary air and gradient flows are simulated respectively by a numerical integration method under short time and spatial length scales. The results indicate that:the terminal linear velocities in the gravity direction and the corresponding stabilization times increase with the average particle size and density. Under a specified grain diameter, higher particle densities provide greater motion displacements for snow particles within the same period. In the conditions of shear flows, smaller wind gradients lead to particle velocity fluctuations in both approaching and gravity directions, the development of aerodynamic forces lags behind the variation of particle velocities, and better flow-following abilities are produced by strong wind. The assumption of local equilibrium over short time and spatial length scales is applicable for both of the free settlement and forced motion particles in conventional drifting snow.